Abstract

Eucalyptus pulps is extensively used in papermaking (printing, tissue and packaging grades) but it is also used for chemical conversion into cellulose derivatives such as viscose, cellulose-acetate, cellulose-xanthate, carboxymethyl cellulose, and nanocellulose. Among this last derivative, cellulose nanocrystals (CNC) are an attractive emerging material for multiple applications due to its renewable nature, biodegradability, anisotropic shape, available hydroxyl groups for functionalisation, colloidal stability, excellent mechanical properties, and good biocompatibility, among others. The CNCs are crystalline domains extracted form wood through acid hydrolysis. They are rigid, rod-like particles with a width of several nanometers and lengths of up to hundreds of nanometers [4,5]. The characteristics of CNCs depend on the origin of the fibres and hydrolysis conditions (acid concentration, temperature, and reaction time). However, up to now, there is a little information available on structure and properties of the fibrous raw materials and their impact on the subsequent production of CNCs. With the aim to understand the differences and the further use for the production of cellulose nanocrystals, four six-year-old Eucalyptus species with different initial crystallinity were sampled and analysed. The species studied corresponded to E. benthamii, E. globulus, E. smithii and hybrid of E. nitens x E. globulus (coded as En×Eg), which grew under the same field and plantations conditions.